The Great Salt Lake is getting a little less great - here’s why

America’s Great Salt Lake in Utah is well-named.

It’s the biggest salt water lake in the western hemisphere and is prized for its stunning views.

But climate change and population growth are making the Great Salt Lake a bit less great – at least in size.

New pictures from NASA show how the lake has been shrinking since the mid-1980s.

When the Great Salt Lake was at its highest recorded level in 1986, the average water height was 1,283.7 metres.

Since then, the lake has dropped about 6.7 metres, and hit a new record low on 3 July 2022 of 1,277.1 metres. A further fall took the water level to 1,276.9 metres by 10 August.

“Though water levels in the Great Salt Lake can fluctuate by year, they have generally been declining for decades,” NASA’s Earth Observatory says.

Between 1982 and 2022, the population around Salt Lake City in Utah has grown from 700,000 to 1.2 million and more water has been drawn from the area for housing and agriculture.

Climate change and the warming it brings also means water from the atmosphere is falling more as rain instead of snow.

“Snow is better for the lake because it gets stored in the mountains and released slowly,” explained biologist Bonnie Baxter.

The Great Salt Lake could have managed “a few years of drought” until recently, Baxter said. But now, it is in no fit state to “effectively handle the pressures of climate change,” she added.

Since 1850, water inflows to the Great Salt Lake have fallen almost 40% because of people’s use of the water, researchers at Utah State University estimates.

NASA says white fringes around the edge of the lake show where there are newly exposed parts of the lakebed. Different water depths and concentrations of sediment, salt, bacteria, and algae also show as different colours.

The Great Salt Lake contributes an estimated $1.5 billion to Utah’s economy and supports brine shrimp and salt harvesting operations, magnesium mining and recreational activities, NASA says.

The lake’s shallow waters also sustain “millions of migratory birds”.

A separate report from the European Space Agency (ESA) said the falling waters of the Great Salt Lake could have “devastating consequences” for northern Utah’s economy, ecology and people.

As the lake shrinks, it becomes saltier – this “endangers flies and brine shrimp which millions of birds rely on for food,” the ESA explains.

Drying of the lakebed also jeopardizes human health by releasing dust into the air that is “laced with copper, arsenic and other dangerous heavy metals” from the residue of mining activity, it says.